Inflatable plug with flange

ABSTRACT

An inflatable plug insertable into a conduit and inflatable therein to restrict fluid flow comprises a bladder having an interior surface and an exterior surface and at least one fabric layer covering at least a portion of the exterior surface of the bladder. The inflatable plug also comprises a first plate, a second plate, and at least one fluid port. The first plate is positioned inside the bladder and adjacent to the interior surface of the bladder. The second plate is positioned outside the bladder and adjacent to the at least one fabric layer. The second plate is coupled to the first plate such that the first plate and the second plate clamp a portion of the at least one fabric layer and a portion of the bladder therebetween. The at least one fluid port extends through the first plate and the second plate and facilitates inflation and deflation of the bladder.

FIELD

Embodiments of the invention generally relate to inflatable plugs forconduits.

BACKGROUND

Inflatable plugs are used for plugging conduits, such as sewer lines,gas lines, or oil pipelines, to permit maintenance, facilitate toxicwaste containment, or remove blockages. Such plugs couple to fluid linesto facilitate inflation and deflation within conduits.

SUMMARY

The following summary sets forth certain exemplary embodiments of theinvention. It does not set forth all such embodiments and is notlimiting of embodiments of the invention.

In one embodiment, an inflatable plug insertable into a conduit andinflatable therein to restrict fluid flow comprises a bladder having aninterior surface and an exterior surface and at least one fabric layercovering at least a portion of the exterior surface of the bladder. Theinflatable plug also comprises a first plate, a second plate, and atleast one fluid port. The first plate is positioned inside the bladder,adjacent to the interior surface of the bladder. The second plate ispositioned outside the bladder, adjacent to the at least one fabriclayer. The second plate is coupled to the first plate such that thefirst plate and the second plate clamp a portion of the at least onefabric layer and a portion of the bladder therebetween. The at least onefluid port extends through the first plate and the second plate andfacilitates inflation and deflation of the bladder.

In another embodiment, a method of assembling an inflatable plug, whichis insertable into a conduit and inflatable therein to restrict fluidflow, comprises positioning a bladder material having an outer surfaceon top of a first plate, and covering the outer surface of the bladdermaterial with at least one fabric material. The method also includespositioning a second plate on top of the at least one fabric layer,coupling the first plate to the second plate, and forming a closedbladder using at least the bladder material.

Various embodiments herein can allow higher operating pressures thanexisting plugs. Additionally, embodiments herein can be configured forinflation and deflation on an end or on a side of a plug, for example.

Other aspects of the invention will become apparent by consideration ofthe detailed description and accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a system according to an embodiment of the invention.

FIG. 2 shows a top view of an inflatable plug having a flange accordingto an embodiment of the invention.

FIG. 3 shows a partial cross-sectional view of the inflatable plug ofFIG. 2.

FIG. 4 shows an exploded side view of a portion of the inflatable plugof FIG. 2.

FIG. 5 shows a system according to another embodiment of the invention.

FIG. 6 shows an end view of an inflatable plug having a flange accordingto another embodiment of the invention.

FIG. 7 shows a partial cross-sectional view of the inflatable plug ofFIG. 6.

DETAILED DESCRIPTION

Before any embodiments of the invention are explained in detail, it isto be understood that the invention is not limited in its application tothe details of construction and the arrangement of components set forthin the following description or illustrated in the following drawings.The invention is capable of other embodiments and of being practiced orof being carried out in various ways. Also, it is to be understood thatthe phraseology and terminology used herein are for the purpose ofdescription and should not be regarded as limiting. The use of“including,” “comprising,” or “having” and variations thereof herein ismeant to encompass the items listed thereafter and equivalents thereofas well as additional items. Unless specified or limited otherwise, theterms “mounted,” “connected,” “supported,” and “coupled” and variationsthereof are used broadly and encompass both direct and indirectmountings, connections, supports, and couplings. Further, “connected”and “coupled” are not restricted to physical or mechanical connectionsor couplings.

Embodiments of the invention relate to inflatable plugs. While deflated,a plug is insertable into a conduit, such as a sewer line, an oilpipeline, a gas line, or a water main, through a hot tap in the conduit.Once inserted, the plug is inflated to restrict fluid flow through theconduit. Restricting fluid flow permits repair and/or maintenance (e.g.,cleaning, patching holes, etc.) to be performed on the conduit. Invarious embodiments, a flange is positioned on the plug and configuredto couple with fluid lines for inflation and deflation of the plug.

Embodiments of the inflatable plugs described below are adaptable tohave inflation diameters between about 4 inches and 120 inches and arecapable of an inflation pressure up to about 150 pounds per square inchgauge (psig). Additional inflation diameters and pressures may beachieved by adjusting various components of the plugs. Plug lengths mayalso be adjusted depending on the application.

FIG. 1 shows a system 100 according to an embodiment of the invention.The system 100 includes an inflatable plug 110, a tube 115, a packingseal 120, a launch cylinder 125, a valve 130, and a tapping saddle 135.The system 100 is configured for use in a conduit 105. In theillustrated embodiment, the plug 110 is inflated to restrict fluid flowthrough the conduit 105.

The tapping saddle 135 couples to the conduit 105 by bolts, welding, orelectro-fusion. The valve 130 (e.g., a full port valve) is coupled tothe tapping saddle 135 to allow selective access through the tappingsaddle 135 to an interior of the conduit 105 through a hole (e.g., hottap) formed thereon. The launch cylinder 125 couples to the valve 130and guides the tube 115 (e.g., an inflation ram) and the deflated plug110 into the interior of the conduit 105. The packing seal 120 ispositioned around the tube 115 to prevent any fluid in the conduit 105from leaking out through the launch cylinder 125.

The tube 115 is coupled to and in fluid communication with the plug 110via a flange 140. The flange 140 is positioned on a side of the plug 110and couples to the tube 115 to facilitate fluid flow into and out of theplug 110. The flange 140 may be constructed of, for example, metals,ceramics, or high-density plastics. Fluid entering the plug 110 may be,for example, air, nitrogen, water, or other liquids and gases suitablefor inflation of the plug 110. The fluid may also be drawn from the plug110 and through the flange 140 to allow for deflation of the plug 110.

FIG. 2 shows a top view of an inflatable plug 200 having a flange 205according to an embodiment of the invention. The plug 200 and the flange205 are one implementation of the plug 110 and the flange 140 of FIG. 1.The plug 200 is generally cylindrical and includes an inner bladder 330(see FIGS. 3 and 4), a plurality of fabric layers 210, 315, 325 (seeFIGS. 3 and 4), and a plurality of outer straps 220. In the illustratedembodiment, the plug 200 includes eight outer straps 220 spaced apartand positioned adjacent an outermost fabric layer 210. As shown in FIG.2, the outer straps 220 are positioned on an exterior surface of theoutermost fabric layer 210; however, in other embodiments, the outerstraps 220 may be positioned between the outermost fabric layer 210 andan inner fabric layer 315. The outer straps 220 circumferentiallysurround the plug 200 and increase the sealing capabilities of the plug200. The outer straps 220 may be constructed of, for example, lowdurometer butyl rubber, Buna-N rubber, or ballistic nylon. In someembodiments, the outer straps 220 may have a relatively high coefficientof friction to resist sliding of the inflated plug 200 within theconduit 105.

The flange 205 is positioned on a side of the plug 200 and includes atop plate 225 and a bottom plate 310 (see FIG. 3) coupled to the topplate 225 via fasteners 250 (e.g., bolts, screws, nails, etc.). Thefasteners 250 are positioned along a circumference of the top plate 225and extend through the top plate 225, through the fabric layers 210,315, 325 and the bladder 330, to the bottom plate 310. In theillustrated embodiment, the top and bottom plates 225, 310 are circularin shape and positioned such that the bottom plate 310 is aligned withthe top plate 225. In other embodiments, the top and bottom plates 225,310 may be other shapes (e.g., square, octagonal, etc.), and/or may notbe aligned with each other.

The flange 205 includes a water port 240 and an air port 235. In theillustrated embodiment, the water port 240 is positioned in the centerof the flange 205, and the air port 235 is positioned near an edge ofthe flange 205. It should be apparent to one skilled in the art that thepositions of the ports 235, 240 may be exchanged or the positions may bemodified to other suitable locations on the flange 205. Additionally oralternatively, fewer or more ports may be provided to allow fluid flowor to support additional internal or external instrumentation (e.g.,sensors, transducers, detectors, etc.) for plug monitoring.

The water port 240 provides fluid access to an interior region of theplug 200. In the embodiment illustrated in FIGS. 2 and 3, the water port240 is defined by the top plate 225 and the bottom plate 310. Water orother liquids move (e.g., flow) through the water port 240 to inflateand deflate the plug 200. In some embodiments, the water port 240 mayinclude a ball valve with a cam and groove coupling to facilitateconnection of a water line to the water port 240.

The air port 235 also provides fluid access to an interior region of theplug 200. In the embodiment illustrated in FIGS. 2 and 3, the air port235 is defined by the top plate 225 and the bottom plate 310. Air,nitrogen, or other gases flow through the air port 235 to inflate anddeflate the plug 200. In some embodiments, the air port 235 may includea ball valve with a quick connect/disconnect coupling to facilitateconnection of an air line to the air port 235.

In some embodiments, air, not water, is used to initially inflate theplug 200 when the plug 200 is being positioned. As such, the position ofthe plug 200 may be adjusted more easily within the conduit 105. Wateris then injected into the plug 200, exhausting the air through the airport 235 and preventing potential shifting of the plug 200 within theconduit 105.

The flange 205 also includes four bores 255 located radially inward ofthe fasteners 250. The bores 255 are positioned about the water port 240to facilitate coupling of the tube 115 to the flange 205. For example,the tube may include a bracket 400 (see FIG. 4) having correspondingbores. The bores 255 of the flange 205 and the bores of the bracket 400may receive fasteners 420 to secure the tube 115 to the flange 205. Inthe illustrated embodiment, the bores 255 are positioned to couple thebracket 400 and the tube 115 around only the water port 240. In otherembodiments, the bores 255 may be positioned to couple the bracket 400and the tube 115 around both the water port 240 and the air port 235 oraround only the air port 235.

A cushion 230 (e.g., a polyurethane cushion or other suitable cushion)is positioned between the outermost fabric layer 210 and the top plate225. The cushion 230 is generally a shape similar to the top plate 225.During assembly of the top plate 225 on the plug 200, the cushion 230compresses and deforms and may extend slightly past an edge of the topplate 225, as shown in FIG. 2. In some embodiments, a second cushion 405(see FIG. 4) is positioned between the bladder 330 and the bottom plate310. The cushions 230, 405 prevent the top and bottom plates 225, 310from creating stress lines or tears in the bladder 330 and the fabriclayers 210, 315, 325.

FIG. 3 shows a partial cross-sectional view of the plug 200. In theillustrated embodiment, the plug 200 includes the bladder 330, two innerfabric layers 315, 325, a webbing 320, and the outermost fabric layer210. The bladder 330 is the innermost layer and defines the interiorregion of the plug 200. The fabric layers 210, 315, 325 surround andenclose the bladder 330, protecting the bladder 330 from puncturing ortearing. The bladder 330 may be constructed of, for example, apolyurethane or other impermeable material; the inner fabric layers 315,325 may be constructed of a ballistic strength nylon material or Kevlar®(available from DuPont Advanced Fiber Systems of Richmond, Va.); and theoutermost fabric layer 210 may be constructed of a ballistic strengthnitrile-coated nylon material.

The webbing 320 (which may also be constructed of a ballistic strengthnylon material) is positioned between one of the inner fabric layers 315and the outermost fabric layer 210 to increase the strength of the plug200. The webbing 320 extends circumferentially and lengthwise along theplug 200, culminating at each end of the plug 200. In some embodiments,a fabric patch (e.g., a square of webbing material) may be positioned ateach end of the plug 200 such that the webbing 320 may couple to thefabric patch. Additionally or alternatively, more or fewer fabric layers210, 315, 325 and/or webbings 320 may be used to adjust the strength ofthe plug 200.

As shown in FIG. 3, a water tube 305 extends from the water port 240into the plug 200 and an air tube 300 extends from the air port 235 intothe plug 200. The water tube 305 includes a weight 340 coupled to an endopposite from the water port 240, such that the water tube 305 sinks andfills the plug 200 with water from a bottom of the plug 200. The airtube 300 includes a float 335 coupled to an end opposite the air port235, such that the air tube 300 floats on the water and exhausts onlyair from the plug 200. Additionally, the air tube 300 may include apressure gauge to measure the inflation pressure of the plug 200.

FIG. 4 shows an exploded side view of a portion of the plug 200.Assembly of the plug 200 is performed by positioning the bladder 330over the bottom plate 310 and the second cushion 405. The bladder 330 iscovered with the two inner fabric layers 315, 325, the webbing 320, andthe outermost fabric layer 210. The top plate 225 and the cushion 230are positioned on the outermost fabric layer 210, aligned with thebottom plate 310 and the second cushion 405.

The fasteners 250 pass through the top plate 225, the cushions 230, 405,the fabric layers 210, 315, 325, the bladder 330, and the bottom plate310 to couple the top plate 225 and the bottom plate 310. The fasteners250 are tightened (e.g., torqued) to compress the cushions 230, 405 andthe fabric layers 210, 315, 325.

The air port 235 and the water port 240 are also provided through thetop plate 225, the cushions 230, 405, the fabric layers 210, 315, 325,the bladder 330, and the bottom plate 310 to allow fluid communicationbetween an exterior of the plug 200 and the interior region. In theembodiment illustrated in FIG. 4, the air port 235 is provided generallyat line 415, and the water port 240 is provided generally at line 410.In some embodiments, instrumentation and/or fittings, such as ballvalves, may be inserted through the plug layers to define the air port235 and the water port 240.

The fasteners 420 pass through the bracket 400 of the tube 115, the topplate 225, the cushions 230, 405, the fabric layers 210, 315, 325, thebladder 330, and the bottom plate 310 to couple the tube 115 to theflange 205. Similar to the fasteners 250 discussed above, the fasteners420 may be tightened to further compress the cushions 230, 405 and thefabric layers 210, 315, 325.

In some embodiments, the bladder 330, the fabric layers 210, 315, 325,and the cushions 230, 405 may include prior-made slits or cut-outs tofacilitate passing of the fasteners 250, 420 and/or fittings definingthe air port 235 and the water port 240 between the top plate 225 andthe bottom plate 310.

After the flange 205 is secured, edges of the bladder 330 are sewntogether to form a closed bladder. Likewise, edges of the fabric layers210, 315, 325 are sewn together to surround the bladder 330 to form theplug 200. A sealant (e.g., silicone, polyurethane gel, etc.) is appliedto seams formed during sewing to prevent fluid leakage therethrough. Insome embodiments, single pieces of the bladder 330 and the fabric layers210, 315, 325 are used to form the plug 200. In other embodiments,multiple pieces of bladder material and/or fabric material are sewntogether to form the plug 200. In addition, multiple stitches may beused to increase the strength of the plug 200.

FIG. 5 shows a system 500 according to another embodiment of theinvention. The system 500 includes an inflatable plug 510, an air hose515, a water hose 525, an air valve 520, and a water valve 530. Thesystem 500 is configured for use in a conduit 505, and the plug 510 isinsertable into the conduit 505 in a similar manner to that discussedwith reference to FIG. 1. However, in this embodiment, the plug 510 ispositioned in the conduit 505 upstream from a hole through which theplug 510 is inserted. A valve 535 (e.g., a butterfly valve) ispositioned in the conduit 505 downstream from the hole to preventbackflow in the conduit 505 from contacting the air and water hoses 515,525.

The air hose 515 and the water hose 525 are coupled to and in fluidcommunication with the plug 510 via a flange 540. In the illustratedembodiment, the flange 540 is positioned on an end of the plug 510 andcouples to the air hose 515 and the water hose 525 to facilitate fluidflow into and out of the plug 510. The air hose 515 extends from theflange 540 and couples to the air valve 520 (e.g., a ball valve withquick connect/disconnect couplings), and the water hose 525 extends fromthe flange 540 and couples to the water valve 530 (e.g., a ball valvewith cam and groove couplings). The air valve 520 couples to an air line545 which provides air, nitrogen, or other gases through the air hose515 toward the plug 510. The water valve 530 couples to a water line 550which provides water or other fluids through the water hose 525 towardthe plug 510.

In some embodiments, the water hose 525 may be a suction hose, and thewater line 550 may be a suction line. In such embodiments, the plug 510is filled with fluid only through the air hose 515, and the fluid isdischarged from the plug 510 through the suction hose 525. In addition,in some embodiments, the flange 540 may include anchor lugs tofacilitate movement (e.g., dragging) of the inflated plug 510.

A second flange 555 is secured to an end of the plug 510 opposite fromthe flange 540. The second flange 555 includes anchor lugs 560 tofacilitate movement of the inflated plug 510. In some embodiments, thesecond flange 555 may include fluid ports such that the plug 510 may beinflated and deflated at either end.

FIG. 6 shows an end view of an inflatable plug 600 having a flange 605according to another embodiment of the invention. The plug 600 and theflange 605 are one implementation of the plug 510 and the flange 540 ofFIG. 5. In addition, the plug 600 is generally the same in structure andfunction as the inflatable plug 200 discussed with reference to FIGS.2-4, and like parts have been given the same reference numerals.

The flange 605 is positioned on an end of the plug 600 and includes atop plate 610 and a bottom plate 700 (see FIG. 7) coupled to the topplate 610 via fasteners 615 (e.g., bolts, screws, nails, etc.). Thefasteners 615 are positioned along a circumference of the top plate 610and extend through the top plate 610 to the bottom plate 700. In theillustrated embodiment, some of the fasteners 615 include an eye hole620. The eye holes 620 facilitate movement and/or anchoring of the plug600 within the conduit 505.

The flange 605 includes a water port 630 and an air port 625 similar tothe water port 240 and the air port 235 discussed with reference to FIG.2. In the illustrated embodiment, the water port 630 and the air port625 are positioned on radially opposite sides of the flange 605.

FIG. 7 shows a partial cross-sectional view of the inflatable plug 600.As discussed above with reference to FIGS. 2-4, the plug 600 includesthe bladder 330, the inner fabric layers 315, 325, the webbing 320, theoutermost fabric layer 210, and the outer straps 220, similar to theinflatable plug 200.

In addition, the plug 600 includes an air tube 705 with a float 715 anda water tube 710 with a weight 720. The air tube 705, the water tube710, the float 715, and the weight 720 function in a similar manner tothe air tube 300, the water tube 305, the float 335, and the weight 340of the plug 200 discussed above with reference to FIG. 3.

In some embodiments, an inflatable plug may include a flange positionedon an edge and a flange positioned on an end. As such, a single plug maybe positioned in a conduit adjacent to a hot tap in one scenario andupstream from the hot tap in another scenario. The flange may also beoff center for inflation and deflation near a conduit invert or on aportion of the outer surface of the plug.

In other embodiments, an inflatable plug may be a non-cylindrical shape.For example, the plug may be spherical or conical to correspond with theshape of a conduit.

Embodiments described above allow for higher inflation pressures and aremore flexible than existing molded rubber plugs. Embodiments also allowfor easier positioning and insertion of plugs through hot taps andrestricted access into conduits.

Furthermore, in various embodiments, bunching or swaging of material isnot required to couple a flange on a plug, making the plug material lesssusceptible to failure than existing plugs with swaged collars.

Embodiments herein also allow for inflation and deflation on an end oron a side of a plug. In embodiments where a flange is positioned on theside of the plug, the plug does not need to navigate a bend for hot tapinsertion and, therefore, does not require an inflation swivel. Inaddition, a shorter inflation ram and launch cylinder may be used toguide the plug.

Various features and advantages of the invention are set forth in thefollowing claims.

1. An inflatable plug insertable into a conduit and inflatable thereinto restrict fluid flow, the inflatable plug comprising: a bladder havingan interior surface and an exterior surface; at least one fabric layercovering at least a portion of the exterior surface of the bladder; afirst plate positioned inside the bladder and adjacent to the interiorsurface of the bladder; a second plate positioned outside the bladderand adjacent to the at least one fabric layer, the second plate coupledto the first plate, such that the first plate and the second plate clampa portion of the at least one fabric layer and a portion of the bladdertherebetween; and at least one fluid port extending through the firstplate and the second plate to facilitate inflation and deflation of thebladder, wherein the second plate is secured to the first plate by atleast one fastener spaced from the at least one fluid port.
 2. Theinflatable plug of claim 1, wherein the first plate and the second plateare positioned at an end of the bladder.
 3. The inflatable plug of claim1, wherein the first plate and the second plate are positioned at a sideof the bladder.
 4. The inflatable plug of claim 1, wherein the bladderis constructed of a polyurethane material.
 5. The inflatable plug ofclaim 1, wherein the at least one fabric layer includes an outer layer,two inner layers, and a plurality of webbing straps positioned betweenthe outer layer and the two inner layers.
 6. The inflatable plug ofclaim 1, and further comprising a plurality of circumferential outerstraps positioned outside the outer bladder and adjacent to the at leastone fabric layer.
 7. The inflatable plug of claim 1, and furthercomprising a cushion positioned between the bladder and the first plate.8. An inflatable plug insertable into a conduit and inflatable thereinto restrict fluid flow, the inflatable plug comprising: a bladder havingan interior surface and an exterior surface; at least one fabric layercovering at least a portion of the exterior surface of the bladder; afirst plate positioned inside the bladder and adjacent to the interiorsurface of the bladder; a second plate positioned outside the bladderand adjacent to the at least one fabric layer, the second plate coupledto the first plate, such that the first plate and the second plate clampa portion of the at least one fabric layer and a portion of the bladdertherebetween; and at least one fluid port extending through the firstplate and the second plate to facilitate inflation and deflation of thebladder, wherein the at least one fluid port includes an air port tofacilitate movement of air into and out of the bladder, and a water portto facilitate movement of water into and out of the bladder, the airport and the water port at least partially defined by at least one holein the second plate.
 9. The inflatable plug of claim 8, and furthercomprising a tube coupled to the air port, wherein the tube includes afloat and extends into the bladder.
 10. The inflatable plug of claim 1,wherein the at least one fluid port includes a ball valve.
 11. Theinflatable plug of claim 1, wherein the second plate is coupled to thefirst plate by a plurality of bolts.
 12. The inflatable plug of claim11, wherein at least one of the bolts includes an eye hole to facilitateat least one of movement and anchoring of the plug.
 13. The inflatableplug of claim 1, wherein the plug is cylindrical and has a diameterbetween about 4 inches and about 120 inches.
 14. The inflatable plug ofclaim 1, wherein at least one of air, nitrogen, and water flows throughthe at least one fluid port to inflate the bladder.
 15. The inflatableplug of claim 1, wherein the first plate and the second plate havesubstantially the same cross-sectional dimensions such that the firstplate is alignably positioned with the second plate.
 16. A method ofassembling an inflatable plug, the assembled plug insertable into aconduit and inflatable therein to restrict fluid flow, the methodcomprising: positioning a bladder material having an outer surface ontop of a first plate; covering the outer surface of the bladder materialwith at least one fabric layer; positioning a second plate on top of theat least one fabric layer; coupling the first plate to the second platewith at least one fastener; forming a closed bladder using at least thebladder material; and inserting a fluid port through the first plate andthe second plate to facilitate inflation and deflation of the closedbladder wherein the fluid port is spaced from the at least one fastener.17. The method of claim 16, wherein the first plate is coupled to thesecond plate with bolts.
 18. The method of claim 16, wherein forming aclosed bladder includes sewing edges of the bladder material together toform a closed bladder.
 19. The method of claim 16, wherein the bladdermaterial includes a plurality of pieces, and forming a closed bladderincludes connecting the plurality of pieces together to form a closedbladder.
 20. The method of claim 16, and further comprising providing anair port and a water port through the first plate and the second plate.21. The method of claim 20, wherein providing an air port and a waterport includes providing a first pair of holes through the first plateand providing a second pair of holes through the second plate.
 22. Themethod of claim 20, wherein the air port and the water port are the sameport.